Electromagnetic ignition device, particularly for internal combustion engines



L. -TORRIANI 2,297,510 ELECTROMAGNETIC IGNITIO EVICE, PARTICULARLY FOR INTERNAL BUSTION ENGINE Filed Aug. 23, 1940 N D COM Sept. 29, 1942.

Patented Sept. 29, 1942 ELECTROMAGNETIC IGNITION DEVICE, PARTICULARLY FOB INTERNAL COM-.

BUSTION ENGINES Luigi Torriani, Milan, Italy; vested in the Alien Property Custodian Application August 23, 1940, Serial No. 353,865

' In Italy September 1, 1939 l 2 Claims. (Cl. 171-209) For mounting electro-magnetic ignition devices on vehicles, airplanes and the like driven by a combustion engine, it is desirable, from difierent points of view, that these devices should have a perfectly cylindrical external shape.

Ignition devices are already known according to the following features: the primary and secondary windings forming their ignition coils are arranged coaxially on the driving shaft and their armature portion is so constructed that the total magnetic flux passes at the same'time through the ignition coil.

With this construction very great voltage differences between the diiferent layers of the wire take place upon the interruptions in the primary winding, so that perforations often occur in the insulations.

The object of the present invention is to provide an electro-magnetic ignition device, in which the above inconveniences are prevented, notwithstanding the form of the device being perfectly cylindrical.

Such device includes an ignition coil, the primary and secondary windings which form the ignition coil being vertically arranged on the vertical driving shaft of the device.

These windings are wound on the vertical magnetic core, with pole pieces so arranged as to cooperate with a permanent magnet in the form of a fixed ring.

According to the invention, owing to the vertical arrangement of the coil with distributed pole pieces, several inversions of magnetic flux and, therefore, several sparks are obtainable at each revolution of the device.

Th annexed drawing shows, by way of example only and not as a limitation, one embodiment of the present invention.

Fig. 1 is a vertical sectional view of an embodiment of the permanent magnet in the form of a fixed ring;

' Fig. 2 shows the assembly of the permanent I magnet according to Fig. 1;

Fig. 3 is a sectional view of the complete ignition device;

Fig. 4 shows the assembly of the rotary armature;

Fig. 5 shows an embodiment of the distributing brush forminga protection for the rotary armature of Fig. 4.

The vertical permanent magnet consists of 3 sections, I being the top pole piece, 2 the fixed permanent magnet and l the bottom pole piece (see Figs. 1 and 2).

in the form of a ring (Fig. 1) there are indicated the two pole pieces I and 3 and twosynoidal arrows showing the magnetic circuit. N and S indicate north and south polarities.

Referring to Fig. 3, 8 indicates the distribution cover; I! is the high voltage distributing rotary brush; I is the base of the rotary switch device; 9 is the adjustable fixed cam ring for controlling the low voltage rupture of the rotary switch fixed on the base I; 5 indicates the-condenser fixed on the base I; I is the top pole piece fixed on the permanent magnet 2, 3 is the second pole piece fixed on the bottom of the permanent magnet 2.

I3 is the base integral with the driving shaft I5 and joint I6. I 4 indicates the extension for the mounting on'the engine. 24 is the core of the coil which, when assembled, is integral with the vertical driving shaft I5, the latter being integral with the base I3.

Mounted thereupon are the coil core 24 and, besides, on the top and bottom ends, the pole pieces I8, whichenclose the armature 2!, as in Fig. 4. The base of the switch device I is arranged in the upper section integral with the journal 6 (Fig. 3).

I'I-IQ, Figs. 4 and 5, indicate the distributing brush made of insulating material; said brush is madein a single piece in the form of a solid bush to protect the armature coil 2!, enclosed between the top and bottom pole pieces I and 3 provided on the rotor as shown by Fig. 4.

According to the invention, the ignition device has many important advantages in comparison to other known apparatuses havin the same application.

In the ignition apparatuses heretofore known, in which it is necessary to provide a carcase for rotation of the permanent magnet therein to obtain flux inversion and in which the pole pieces have a certain amplitude to energize the armature, it is necessary to provide an opposite carcase, as its overall diameter and height make their mounting rather difficult, specially on engines of recent design.

According to the present invention, however,

the body of the-apparatus is formed by the perma- In the sectional view of the permanent magnet nent magnet 2, in the form of a stationary ring and the apparatus is protected all around against electro-magnetic actions.

The construction according to the present invention, due to the arrangement or the fixed permanent magnet in the form of a ring, at the ends of which pieces I and 3 are mounted, allows for any distribution desired of the pole pieces.

With this arrangement of the pole pieces, ac-

it is known, to provide ignition devices .with reduction gears.

According to the invention, the present ignition device is completely devoid of gears and can supply any desired number oi! sparks at each revolution, because it is known that this device, being mounted on the cam shaft of the engine, rotates at half the speed of the driving shaft.

To obtain odd ignitions by said apparatus, it is necessary that the pole pieces of the rotary armature be also distributed in an odd number both inferiorly and superlorly.

The distributing brush according to the present invention is made in the form of a bush with an integral extension, this extension being provided to distribute the high voltage to the distribution cover, the brush serving also to thoroughly protect the armature. p

The ignition distributing brushes of known apparatuses undergo considerable losses, as their insulating portions adhere to mechanical parts.

These drawbacks are totally avoided with the ignition device according to the present invention, due to the employment of this distributing brush in the form of a bush which is mounted on the rotating armature forming a unit therewith and, by its rotation, carries out the transmission directly to the distribution cover, insuring a high eihciency of the ignition device.

It is to be understood that constructional and shape details may vary without exceeding the scope of the invention.

What I claim is: 1. An ignition magneto comprising, an annular permanent magnet having a North polarity at one end and a South polarity at the other end,

a plurality of circumferentially spaced pole pieces magnetically engaging, the North end of said permanent magnet and extending inside the an-' nular magnet towards the South end thereof, a

series' of pole pieces magnetically engaging the 7 South end of the permanent magnet and extending inside the annular permanent magnet between the first pole pieces and towards the North end of the-permanent magnet so as to overlap the first pole pieces, amagnetizabie core mounted for rotation within said annular permanent magnet, and'a winding on said core.

2. An ignition magneto comprising, an annular permanent magnet having a North polarity at timer 'ronarsm. 

